linux/drivers/nvmem/rockchip-efuse.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Rockchip eFuse Driver
   4 *
   5 * Copyright (c) 2015 Rockchip Electronics Co. Ltd.
   6 * Author: Caesar Wang <wxt@rock-chips.com>
   7 */
   8
   9#include <linux/clk.h>
  10#include <linux/delay.h>
  11#include <linux/device.h>
  12#include <linux/io.h>
  13#include <linux/module.h>
  14#include <linux/nvmem-provider.h>
  15#include <linux/slab.h>
  16#include <linux/of.h>
  17#include <linux/of_platform.h>
  18#include <linux/platform_device.h>
  19
  20#define RK3288_A_SHIFT          6
  21#define RK3288_A_MASK           0x3ff
  22#define RK3288_PGENB            BIT(3)
  23#define RK3288_LOAD             BIT(2)
  24#define RK3288_STROBE           BIT(1)
  25#define RK3288_CSB              BIT(0)
  26
  27#define RK3328_SECURE_SIZES     96
  28#define RK3328_INT_STATUS       0x0018
  29#define RK3328_DOUT             0x0020
  30#define RK3328_AUTO_CTRL        0x0024
  31#define RK3328_INT_FINISH       BIT(0)
  32#define RK3328_AUTO_ENB         BIT(0)
  33#define RK3328_AUTO_RD          BIT(1)
  34
  35#define RK3399_A_SHIFT          16
  36#define RK3399_A_MASK           0x3ff
  37#define RK3399_NBYTES           4
  38#define RK3399_STROBSFTSEL      BIT(9)
  39#define RK3399_RSB              BIT(7)
  40#define RK3399_PD               BIT(5)
  41#define RK3399_PGENB            BIT(3)
  42#define RK3399_LOAD             BIT(2)
  43#define RK3399_STROBE           BIT(1)
  44#define RK3399_CSB              BIT(0)
  45
  46#define REG_EFUSE_CTRL          0x0000
  47#define REG_EFUSE_DOUT          0x0004
  48
  49struct rockchip_efuse_chip {
  50        struct device *dev;
  51        void __iomem *base;
  52        struct clk *clk;
  53};
  54
  55static int rockchip_rk3288_efuse_read(void *context, unsigned int offset,
  56                                      void *val, size_t bytes)
  57{
  58        struct rockchip_efuse_chip *efuse = context;
  59        u8 *buf = val;
  60        int ret;
  61
  62        ret = clk_prepare_enable(efuse->clk);
  63        if (ret < 0) {
  64                dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
  65                return ret;
  66        }
  67
  68        writel(RK3288_LOAD | RK3288_PGENB, efuse->base + REG_EFUSE_CTRL);
  69        udelay(1);
  70        while (bytes--) {
  71                writel(readl(efuse->base + REG_EFUSE_CTRL) &
  72                             (~(RK3288_A_MASK << RK3288_A_SHIFT)),
  73                             efuse->base + REG_EFUSE_CTRL);
  74                writel(readl(efuse->base + REG_EFUSE_CTRL) |
  75                             ((offset++ & RK3288_A_MASK) << RK3288_A_SHIFT),
  76                             efuse->base + REG_EFUSE_CTRL);
  77                udelay(1);
  78                writel(readl(efuse->base + REG_EFUSE_CTRL) |
  79                             RK3288_STROBE, efuse->base + REG_EFUSE_CTRL);
  80                udelay(1);
  81                *buf++ = readb(efuse->base + REG_EFUSE_DOUT);
  82                writel(readl(efuse->base + REG_EFUSE_CTRL) &
  83                       (~RK3288_STROBE), efuse->base + REG_EFUSE_CTRL);
  84                udelay(1);
  85        }
  86
  87        /* Switch to standby mode */
  88        writel(RK3288_PGENB | RK3288_CSB, efuse->base + REG_EFUSE_CTRL);
  89
  90        clk_disable_unprepare(efuse->clk);
  91
  92        return 0;
  93}
  94
  95static int rockchip_rk3328_efuse_read(void *context, unsigned int offset,
  96                                      void *val, size_t bytes)
  97{
  98        struct rockchip_efuse_chip *efuse = context;
  99        unsigned int addr_start, addr_end, addr_offset, addr_len;
 100        u32 out_value, status;
 101        u8 *buf;
 102        int ret, i = 0;
 103
 104        ret = clk_prepare_enable(efuse->clk);
 105        if (ret < 0) {
 106                dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
 107                return ret;
 108        }
 109
 110        /* 128 Byte efuse, 96 Byte for secure, 32 Byte for non-secure */
 111        offset += RK3328_SECURE_SIZES;
 112        addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
 113        addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
 114        addr_offset = offset % RK3399_NBYTES;
 115        addr_len = addr_end - addr_start;
 116
 117        buf = kzalloc(array3_size(addr_len, RK3399_NBYTES, sizeof(*buf)),
 118                      GFP_KERNEL);
 119        if (!buf) {
 120                ret = -ENOMEM;
 121                goto nomem;
 122        }
 123
 124        while (addr_len--) {
 125                writel(RK3328_AUTO_RD | RK3328_AUTO_ENB |
 126                       ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
 127                       efuse->base + RK3328_AUTO_CTRL);
 128                udelay(4);
 129                status = readl(efuse->base + RK3328_INT_STATUS);
 130                if (!(status & RK3328_INT_FINISH)) {
 131                        ret = -EIO;
 132                        goto err;
 133                }
 134                out_value = readl(efuse->base + RK3328_DOUT);
 135                writel(RK3328_INT_FINISH, efuse->base + RK3328_INT_STATUS);
 136
 137                memcpy(&buf[i], &out_value, RK3399_NBYTES);
 138                i += RK3399_NBYTES;
 139        }
 140
 141        memcpy(val, buf + addr_offset, bytes);
 142err:
 143        kfree(buf);
 144nomem:
 145        clk_disable_unprepare(efuse->clk);
 146
 147        return ret;
 148}
 149
 150static int rockchip_rk3399_efuse_read(void *context, unsigned int offset,
 151                                      void *val, size_t bytes)
 152{
 153        struct rockchip_efuse_chip *efuse = context;
 154        unsigned int addr_start, addr_end, addr_offset, addr_len;
 155        u32 out_value;
 156        u8 *buf;
 157        int ret, i = 0;
 158
 159        ret = clk_prepare_enable(efuse->clk);
 160        if (ret < 0) {
 161                dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
 162                return ret;
 163        }
 164
 165        addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
 166        addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
 167        addr_offset = offset % RK3399_NBYTES;
 168        addr_len = addr_end - addr_start;
 169
 170        buf = kzalloc(array3_size(addr_len, RK3399_NBYTES, sizeof(*buf)),
 171                      GFP_KERNEL);
 172        if (!buf) {
 173                clk_disable_unprepare(efuse->clk);
 174                return -ENOMEM;
 175        }
 176
 177        writel(RK3399_LOAD | RK3399_PGENB | RK3399_STROBSFTSEL | RK3399_RSB,
 178               efuse->base + REG_EFUSE_CTRL);
 179        udelay(1);
 180        while (addr_len--) {
 181                writel(readl(efuse->base + REG_EFUSE_CTRL) | RK3399_STROBE |
 182                       ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
 183                       efuse->base + REG_EFUSE_CTRL);
 184                udelay(1);
 185                out_value = readl(efuse->base + REG_EFUSE_DOUT);
 186                writel(readl(efuse->base + REG_EFUSE_CTRL) & (~RK3399_STROBE),
 187                       efuse->base + REG_EFUSE_CTRL);
 188                udelay(1);
 189
 190                memcpy(&buf[i], &out_value, RK3399_NBYTES);
 191                i += RK3399_NBYTES;
 192        }
 193
 194        /* Switch to standby mode */
 195        writel(RK3399_PD | RK3399_CSB, efuse->base + REG_EFUSE_CTRL);
 196
 197        memcpy(val, buf + addr_offset, bytes);
 198
 199        kfree(buf);
 200
 201        clk_disable_unprepare(efuse->clk);
 202
 203        return 0;
 204}
 205
 206static struct nvmem_config econfig = {
 207        .name = "rockchip-efuse",
 208        .stride = 1,
 209        .word_size = 1,
 210        .read_only = true,
 211};
 212
 213static const struct of_device_id rockchip_efuse_match[] = {
 214        /* deprecated but kept around for dts binding compatibility */
 215        {
 216                .compatible = "rockchip,rockchip-efuse",
 217                .data = (void *)&rockchip_rk3288_efuse_read,
 218        },
 219        {
 220                .compatible = "rockchip,rk3066a-efuse",
 221                .data = (void *)&rockchip_rk3288_efuse_read,
 222        },
 223        {
 224                .compatible = "rockchip,rk3188-efuse",
 225                .data = (void *)&rockchip_rk3288_efuse_read,
 226        },
 227        {
 228                .compatible = "rockchip,rk3228-efuse",
 229                .data = (void *)&rockchip_rk3288_efuse_read,
 230        },
 231        {
 232                .compatible = "rockchip,rk3288-efuse",
 233                .data = (void *)&rockchip_rk3288_efuse_read,
 234        },
 235        {
 236                .compatible = "rockchip,rk3368-efuse",
 237                .data = (void *)&rockchip_rk3288_efuse_read,
 238        },
 239        {
 240                .compatible = "rockchip,rk3328-efuse",
 241                .data = (void *)&rockchip_rk3328_efuse_read,
 242        },
 243        {
 244                .compatible = "rockchip,rk3399-efuse",
 245                .data = (void *)&rockchip_rk3399_efuse_read,
 246        },
 247        { /* sentinel */},
 248};
 249MODULE_DEVICE_TABLE(of, rockchip_efuse_match);
 250
 251static int rockchip_efuse_probe(struct platform_device *pdev)
 252{
 253        struct resource *res;
 254        struct nvmem_device *nvmem;
 255        struct rockchip_efuse_chip *efuse;
 256        const void *data;
 257        struct device *dev = &pdev->dev;
 258
 259        data = of_device_get_match_data(dev);
 260        if (!data) {
 261                dev_err(dev, "failed to get match data\n");
 262                return -EINVAL;
 263        }
 264
 265        efuse = devm_kzalloc(dev, sizeof(struct rockchip_efuse_chip),
 266                             GFP_KERNEL);
 267        if (!efuse)
 268                return -ENOMEM;
 269
 270        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 271        efuse->base = devm_ioremap_resource(dev, res);
 272        if (IS_ERR(efuse->base))
 273                return PTR_ERR(efuse->base);
 274
 275        efuse->clk = devm_clk_get(dev, "pclk_efuse");
 276        if (IS_ERR(efuse->clk))
 277                return PTR_ERR(efuse->clk);
 278
 279        efuse->dev = dev;
 280        if (of_property_read_u32(dev->of_node, "rockchip,efuse-size",
 281                                 &econfig.size))
 282                econfig.size = resource_size(res);
 283        econfig.reg_read = data;
 284        econfig.priv = efuse;
 285        econfig.dev = efuse->dev;
 286        nvmem = devm_nvmem_register(dev, &econfig);
 287
 288        return PTR_ERR_OR_ZERO(nvmem);
 289}
 290
 291static struct platform_driver rockchip_efuse_driver = {
 292        .probe = rockchip_efuse_probe,
 293        .driver = {
 294                .name = "rockchip-efuse",
 295                .of_match_table = rockchip_efuse_match,
 296        },
 297};
 298
 299module_platform_driver(rockchip_efuse_driver);
 300MODULE_DESCRIPTION("rockchip_efuse driver");
 301MODULE_LICENSE("GPL v2");
 302